When a submarine is snorkeling in order to charge the submarine batteries, the exhaust gases from the charging diesel must be removed from the submarine. For this purpose, it is known for an exhaust gas line to be provided in or adjacent to the snorkel mast, from which the exhaust gases emerge in such a manner that they do not mix with the fresh air being sucked in for the charging diesel. This has the disadvantage that an exhaust gas plume is created, which can be detected easily and reveals the presence of the submarine.
In order to avoid this disadvantage, it is known, for example from DE 103 14 057 B3, for the exhaust gases to actually be carried out in the head of the snorkel mast, which is still located underwater, at the same time reducing the water drag on the snorkel mast head in the process. In this case, the exhaust gas emerges without open-loop or closed-loop control through free cross sections in the casing tube of the exhaust gas snorkel mast head that is formed. This has the disadvantage that the exhaust gas snorkel mast has a large volume, with correspondingly high water drag. Furthermore, the mixing of the exhaust gas and water is not so fine that exhaust gas bubbles cannot rise to the surface of the water, where they form an exhaust-gas trail, which can give away the presence of the submarine. Furthermore, a certain amount of resistance to the exhaust gas outlet from the charging diesel must be overcome.